As with most viral illnesses, influenza needs to run its course. Those suffering from influenza can use a painkiller such as paracetamol to help relieve headache and muscle ache and to reduce their temperature. In some countries the antiviral agents amantadine and rimantadine are available to treat influenza A infections: both are equally effective but amantadine can cause neurological and rimantadine gastrointestinal adverse effects. In addition, drug resistance to both of these agents appears to arise frequently. 　　

　　Neuraminidase inhibitors are a new class of medicines for influenza; they are aimed at treating the underlying cause of the illness (i.e. influenza virus replication), not just the symptoms. These antiviral drugs may decrease the length of time that symptoms persist by 1 to 2.5 days if started within 48 hours of onset. At present, zanamivir (Relenza？) and oseltamivir (Tamiflu？) are registered for influenza treatment in Europe. Oseltamivir (Tamiflu？) can also be used for prophylaxis (e.g. if influenza gets a foothold in a closed community like a nursing home or hospital ward, it can be used to protect the residents or patients from succumbing to the infection).